Injection system and method for releasing gas or vapor from a solid material

ABSTRACT

A system to deliver gas/vapor from solid materials. Specifically, the delivery system for the use of gas or vapor released from a solid material, such as a non-aqueous/solid hydrogen peroxide complex. The system is comprised of a delivery system that is configured to receive a plurality of disks containing the solid material and provide these disks into an injector. The injector heats the disks to produce a gas or vapor that is then provided into a chamber. The sterilization process can be done by gas or vapor alone, or in combination with plasma or ultra violet radiation. In particular, a control system automatically induces the delivery system to provide the injector with a disk and then remove the disk once the injection sequence is complete.

This Application is a division of application Ser. No. 08/744,741, filedon Oct. 28, 1996, which is a continuation in part of U.S. patentapplication Ser. No. 08/549,425, filed Oct. 27, 1995, now U.S. Pat. No.5,667,753.

FIELD OF THE INVENTION

1. Field of the Invention

The present invention generally relates to techniques using hydrogenperoxide released from hydrogen peroxide complexes for sterilizingarticles such as medical instruments and materials.

2. Description of the Related Art

Modern medical and dental practices require the use of aseptic materialsand devices, i.e., the materials and devices must be generally free fromgerms, bacteria, etc., and many of these devices are meant for repeateduse. However, in order to achieve this asepsis, efficient sterilizationprocesses are needed for treatment of reusable materials and devices.These processes are needed not only at hospitals and dental offices, butalso at the manufacturers of these materials and devices.

Medical instruments have traditionally been sterilized using eitherheat, as is provided by steam, or a chemicals such as formaldehyde orethylene-oxide gas or vapor state. Each of these methods has drawbacks.Many medical devices, such as fiber optic devices, endoscopes, powertools, etc., are sensitive to heat, moisture, or both. Formaldehyde andethylene oxide are both toxic gases that pose a potential hazard tohealth care workers. Problems with ethylene oxide are particularlysevere, because its use requires long aeration times to remove the gasfrom articles that have been sterilized. This makes the sterilizationcycle time undesirably long. In addition, both formaldehyde and ethyleneoxide require the presence of a substantial amount of moisture in thesystem. Thus, the device to be sterilized must be humidified before thechemical is introduced or the chemical and moisture are introducedsimultaneously. Moisture plays a role in sterilization with a variety ofother chemicals in the gas or vapor state, in addition to ethylene oxideor formaldehyde.

Sterilization using hydrogen peroxide vapor has been shown to have someadvantages over other chemical sterilization processes, and thecombination of hydrogen peroxide with plasma provides additionaladvantages. Hydrogen peroxide vapor can be generated from aqueoushydrogen peroxide solutions or from solid hydrogen peroxide complexes.However, the use of hydrogen peroxide in aqueous solutions of hydrogenperoxide to generate hydrogen peroxide vapor for sterilization may causeproblems. At higher pressures, such as atmospheric pressure, excesswater in the system can cause condensation. Thus, the relative humidityin the sterilization enclosure must be reduced before introducing theaqueous hydrogen peroxide vapor.

The sterilization of articles containing diffusion-restricted areas,such as long narrow lumens, presents a special challenge for hydrogenperoxide vapor that has been generated from an aqueous solution ofhydrogen peroxide. The first problem arises because water has a highervapor pressure than hydrogen peroxide and will vaporize faster thanhydrogen peroxide from an aqueous solution. Another problem is thatwater has a lower molecular weight than hydrogen peroxide and willdiffuse faster than hydrogen peroxide in the vapor state. Therefore,when an aqueous solution of hydrogen peroxide is vaporized, the waterreaches the items to be sterilized first in a higher concentration. Thewater vapor, therefore, becomes a barrier to the penetration of hydrogenperoxide vapor into diffusion restricted areas, such as small crevicesand long narrow lumens.

This problem cannot be solved by removing water from the aqueoussolution and using more concentrated hydrogen peroxide, sinceconcentrated solutions of hydrogen peroxide, i.e., greater than 65% byweight, can be hazardous due to the oxidizing nature of the solution.The shortcomings of aqueous hydrogen peroxide sterilizers of the priorart are overcome by using a non-aqueous source of hydrogen peroxidewhich releases a non-aqueous hydrogen peroxide vapor. In theseprocesses, a solid peroxide complex is heated in a vaporizer and thevapor is diffused into the sterilization chamber.

SUMMARY OF THE INVENTION

One aspect of the present invention is a package for containing a solidmaterial which releases gas or vapor upon heating. This package includesa gas permeable membrane, and the solid material which releases gas orvapor upon heating. The solid material is sealed underneath the gaspermeable membrane. The solid material can be in the form of a powder,tablet or dried slurry. One exemplary type of solid material would be ahydrogen peroxide complex. Other exemplary types of solid materialinclude a hydrate complex or an ammonia complex. The solid materialpreferably releases gas or vapor at a temperature within the range20-300° C., more preferably within the range 25-250° C. In oneembodiment, the package includes a conductive foil, with the solidmaterial between the gas permeable membrane and the conductive foil. Thefoil preferably has a reflective outer surface configured to reflectradiant heat away from the solid material. In another embodiment, thepackage includes an impermeable membrane, with the solid materialbetween the gas permeable membrane and the impermeable membrane.Exemplary materials for the impermeable membrane of this embodimentinclude Mylar™, polycarbonate and PTFE material. Preferably, theimpermeable membrane is transparent to radiation, such as infra-red,microwaves or radio frequency. Where the impermeable material istransparent to radiation, a susceptor can be added which is excitable bythe radiation. Such a susceptor can be a screen adjacent the solidmaterial, where the screen provides pockets holding the solid material.A susceptor, such as a metallic powder or carbon black can also be mixedwith solid material. In embodiments having a foil or impermeablemembrane, an adhesive material, such as a tape, on the inner surface ofthe foil or impermeable material can be provided to which the solidmaterial is adhered. The foil or impermeable material can also beembossed to provide pockets which hold the solid material. Exemplaryembossing patterns include hexagonal or rectilinear patterns. Animpermeable material can also be sealed over the permeable membrane,such that the solid material will be sealed within the package until theimpermeable material is ruptured. Preferably, the melting point of thegas permeable membrane is higher than the release temperature of thesolid material. A perforated material or screen can optionally beincluded outside of the gas permeable membrane. Such a perforatedmaterial or screen is especially useful in packages where the gaspermeable membrane is of glass filter material. The package can alsoinclude a screen adjacent the solid material. Such a screen can providepockets holding the solid material. The screen can be conductive of heatso as to improve heat transfer to the solid material. The package can beincorporated into a support which is capable of being handled. Thesupport can be configured to form a seal to enclose the solid material.Where the support forms a seal, the support can be provided withperforations around the package so as to permit gas or vapor releasedfrom the solid material and through the gas permeable membrane to bedelivered to an opposing side of the package. The gas permeable materialcan be heat-sealed or sealed using an adhesive to enclose the solidmaterial.

Another aspect of the present invention relates to a cartridge housing.The cartridge housing includes a plurality of packages for containing asolid material which releases gas or vapor upon heating. Each of thepackages includes gas permeable membrane, and the solid material whichreleases gas or vapor upon heating. The solid material is sealed withinthe gas permeable membrane. The plurality of packages are preferablystacked so that each of the packages can be activated one at a time.Each of the packages can have at least one edge joined to at least oneedge of another of the packages, so that the plurality of packages canbe folded in a Z-fold or rolled. If the packages are rolled, they arepreferably rolled onto a core. The packages can also be arranged aroundthe periphery of a disk. In some embodiments, the packages are sealedwithin the housing In such embodiments, the cartridge can be configuredto trap gas or vapor released from the solid material within thehousing, such as by providing an impermeable material sealed over thehousing, such that the packages will be sealed within the housing untilthe impermeable material is ruptured. The cartridge housing can beadapted to protect the packages therewithin from a heating source.

Still another aspect of the invention relates to a method of releasinggas or vapor from a solid material capable of releasing the gas orvapor. The method includes providing the solid material sealed within agas permeable material, and heating the solid material, therebyreleasing the gas or vapor through the gas permeable material. The solidmaterial can advantageously be a hydrogen peroxide complex. Thus, themethod can also include contacting hydrogen peroxide released from thecomplex with an object to be disinfected or sterilized. If disinfectionor sterilization is desired, the method can also include contacting theobject with plasma or ultraviolet radiation. The solid material can besealed between the gas permeable material and a conductive foil when theheating step comprises conductive heating. The heating step can alsocomprise irradiative heating. For such methods, it is preferable thatthe solid material be sealed between the gas permeable material and animpermeable material. The irradiative heating can use radiation such asinfra-red, microwaves or radio frequency. The wavelength of theirradiation is preferably selected to excite the solid material torelease the gas or vapor. In a preferred embodiment, the solid materialis in contact with a susceptor which is excitable by radiation causingthe irradiative heating. The susceptor could be a screen adjacent thesolid material or a material mixed with the solid material. Preferably,the wavelength of the irradiation is selected to excite the susceptor soas to cause it to be heated. The heating can also involve convectionheating.

Yet another aspect of the invention relates to an injection system forconductively heating packages containing a solid material which releasesgas or vapor upon heating. This system includes a housing with a gaspermeable plate which is adapted to press on a first side of thepackage, an opening in the housing through which the package can beinserted, and a heatable surface which is adapted to press on a secondside of the package away from the first side thereof. The gas permeableplate is preferably rigid, and the heatable surface is preferablymounted on a carriage adapted to move the heatable surface into contactwith the second side of the package. The gas or vapor released from thesolid material can be released into a first chamber, and the carriageprovided with a seal adapted to create a passageway through which thegas or vapor released from the solid material can pass into a secondchamber when the heatable surface is in contact with the second side ofthe package. When the heatable surface is not in contact with the secondside of the package, the first and second chambers are preferably sealedfrom each other. The carriage can advantageously be adapted to move froma first position wherein the heatable surface is away from the packageto a second position wherein the heatable surface is in contact with thepackage as a result of pressure differences between the first chamberand a bellows chamber. Thus, the system can also be provided with aspring to move the carriage from the second position to the firstposition when the pressure difference between the first chamber and thebellows chamber is approximately zero. As can be appreciated from theforegoing summary of the system, the opening is preferably sealable;however the opening need not be sealable. In one embodiment, the openingseals directly to the package, and other embodiments, the opening sealsto a support upon which the package is mounted or to a mechanism whichcarries the package.

Still one more aspect of the invention relates to a method of releasinggas or vapor from a package containing a solid material which releasesgas or vapor upon heating. The method includes providing a housing witha gas permeable plate therein, inserting the package into an opening inthe housing so as to place a first side of the package into anorientation facing the plate, pressing a heatable surface onto a secondside of the package away from the first side thereof, thereby pressingsaid first side against the plate and heating the package so as torelease gas or vapor therefrom. The second side of the packagepreferably comprises a conductive foil, wherein the conductive foil isheated by conductive heating from the heatable surface.

Yet one more aspect of the invention relates to a delivery system fordelivering a plurality of packages containing a solid material capableof releasing gas or vapor upon heating, to an injection system. Thisaspect of the invention includes a source cartridge containing aplurality of the packages, an upper delivery member that has a firstaperture configured to receive the source cartridge and a secondaperture adapted to receive the destination cartridge, a lower deliverymember that has at least one aperture that is configured to receive oneor more of the packages from the source cartridge, the lower deliverymember being movable so that the package can be positioned in an openingin the injection system, and further movable to deliver used packages toa destination. In a preferred embodiment, the destination is adestination cartridge for receiving the packages after they are used. Inthis embodiment, the upper delivery member preferably includes a secondaperture adapted to receive the destination cartridge. Each of the upperand lower delivery members is preferably a carousel. The delivery systemcan also include a controller which induces the delivery system toprovide a package to the injection system. The controller is preferablyadapted to enable a vacuum source which is adapted to pneumaticallyattach and detach the packages thereto. Thus, the vacuum source can beenabled to retrieve and place the packages. In one preferred embodiment,the vacuum source makes use of suction cups to attach and detach thepackages. In a preferred embodiment, the upper delivery member providesa single point of access to put in and take out the packages.

One more aspect of the invention relates to a method of delivering aplurality of packages containing a solid material capable of releasinggas or vapor upon heating to an injection system. This method includes(a) placing the plurality of packages in a source cartridge, (b) placingthe source cartridge in a first aperture of an upper delivery member,(c) placing a destination cartridge in a second aperture of the upperdelivery member, (d) moving a package from the source cartridge to anaperture in a lower delivery member, (e) moving the lower deliverymember so as to position the package which has been moved to theaperture in the lower delivery member in an opening in the injectionsystem, (f) releasing gas or vapor from the package in the injectionsystem, and (g) moving the lower delivery member so as to deliver thepackage from which gas or vapor has been released to the destinationcartridge. Steps (e) and (g) preferably comprise rotational movement ofthe lower delivery member, and can be accomplished by activating acontroller in order to effect movement of the lower delivery member. Thecontroller can be adapted to enable a vacuum source which pneumaticallyretrieves the packages so as to accomplish step (d), and optionallysteps (e) and (g) as well. An optional step is (h) removing thedestination cartridge. Steps (a) and (h) can be performed through asingle point of access. In a preferred embodiment of the method, theinjection system is sealed with the package therein from step (e).

An additional aspect of the invention relates to a sterilization system.This system includes a delivery system configured to receive a pluralityof packages containing a solid material which releases gas or vapor whenheated, a sterilization chamber that is configured to receive articlesto be sterilized, an injector that receives at least one of theplurality of packages from the delivery system, wherein the injectorheats the solid material so as to produce gas or vapor therefrom andthen guides the gas or vapor into the sterilization chamber, acontroller that induces the delivery system to provide a package to theinjector and induce the injector to produce the gas or vapor during asterilization sequence. Advantageously, the gas or vapor can be hydrogenperoxide when the solid material is a complex of hydrogen peroxide. Thesystem can be configured to receive a cartridge containing the pluralityof packages. A first delivery member can be provided that has one ormore apertures that are configured to receive a source cartridgecontaining a plurality of packages and are also configured to receive adestination cartridge wherein used packages will be positioned thereinfollowing a sterilization sequence. In a preferred embodiment, the firstdelivery member is comprised of an upper carousel. The delivery systemalso preferably includes a second delivery member that has at least oneaperture that is configured to receive a package from the cartridge andwherein the second delivery member is movable so that the package can bepositioned in an opening in the injector by the second delivery member.The second delivery member is preferably comprised of a lower carousel.In one embodiment, the packages are comprised of a package having asolid hydrogen peroxide component encapsulated within an enclosure thathas an impermeable film and a gas permeable surface, wherein the gaspermeable surface permits gaseous hydrogen peroxide to vent from thepackage when the package is heated by the heat source. In a preferredembodiment, the impermeable film is a conductive foil, which preferablyhas a reflective outer surface. The impermeable film can be configuredto reflect radiant heat until a heat source is positioned in contactwith the reflective surface. A preferred injector for use in the systemincludes a housing that defines a first chamber, a heat source, and acarriage that is attached to the heat source and is movable between afirst position and a second position wherein the heat source is incontact with the package when the carriage is in the second position.The one or more communication passageways can interconnect the firstchamber and the sterilization chamber and the carriage configured sothat when the carriage is in the second position, the passagewaysprovide a pathway for gaseous hydrogen peroxide to flow from the firstchamber into the sterilization chamber. The injector can include asecond chamber that functions as a bellows chamber that is at the sameor lower pressure than the first chamber when the carriage is in thefirst position and wherein the first chamber is brought to a lowerpressure than the bellows chamber so as to induce the carriage to movetowards the package.

An additional aspect of the invention relates to a sterilization systemthat provides a sterilizing gas to a sterilizing chamber. This systemincludes a delivery system that receives a plurality of solidsterilization fuel components, an injector that receives one of theplurality of solid sterilization fuel components and induces thecomponent to produce the sterilization gas and further induces thesterilization gas to enter the sterilization chamber, and a controlsystem that induces the delivery system to automatically deliver one ofthe solid sterilization fuel components to the injector and furtherinduces the injector to produce the sterilization gas from the solidsterilization fuel component. The solid sterilization fuel componentpreferably produces non-aqueous vapor that can sterilize objectspositioned within the sterilization chamber. Thus, the solidsterilization fuel can be comprised of a solid hydrogen peroxide complexthat is induced to produce hydrogen peroxide gas in the injector.Optionally, the system can include a source of ultraviolet radiation orplasma. The injector for use in the system can include a housing thatdefines a first chamber, a heat source, and a carriage that is attachedto the heat source and is movable between a first position and a secondposition wherein heat source is in contact with the solid fuel componentwhen the carriage is in the second position. The one or morecommunication passageways can interconnect the first chamber and thesterilization chamber and the carriage configured so that when thecarriage is in the second position, the passageways provide a pathwayfor gaseous hydrogen peroxide to flow from the first chamber into thesterilization chamber. The injector can include a second chamber thatfunctions as a bellows chamber that is at the same or lower pressurethan the first chamber when the carriage is in the first position andwherein the first chamber is at a lower pressure than the bellowschamber so as to induce the carriage to move towards the package. Thedelivery system can also be configured to receive a cartridge containingthe plurality of packages. Thus, the delivery system can include anupper carousel that has one or more apertures that are configured toreceive a source cartridge containing a plurality of packages and arealso configured to receive a destination cartridge wherein used packageswill be positioned therein following a sterilization sequence. Thesystem can also be provided with a lower carousel that has at least oneaperture that is configured to receive a package from the cartridge andwherein the lower carousel is movable so that the package can bepositioned in an opening in the injector by the lower carousel.Preferably, the packages are comprised of a package having a solidhydrogen peroxide component encapsulated within an enclosure that has animpermeable film and a gas permeable surface, wherein the impermeablefilm is configured to reflect radiant heat until a heat source ispositioned in contact with the reflective surface and wherein said gaspermeable surface permits gaseous hydrogen peroxide to vent from saidpackage when said package is heated by said heat source.

One additional aspect of the invention relates to a method ofsterilizing a plurality of objects positioned within a sterilizationchamber. This method includes positioning one of a plurality of solidsterilization fuel components within an injector, inducing the one ofthe plurality of solid sterilization fuel component to produce anon-aqueous sterilization gas, and inducing the non-aqueoussterilization gas to flow from the injector into the sterilizationchamber to sterilize the articles contained therein. The sterilizationgas is preferably hydrogen peroxide. In one embodiment of the method thearticles are also exposed to plasma or ultraviolet irradiation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic of a sterilization chamber equipped with theinjection system of the present invention;

FIG. 1B is a block diagram representing the control system of thepresent invention;

FIG. 2A is a schematic exploded view of a first embodiment of adisk-shaped container including a solid material which releases vapor orgas between a permeable membrane and a conductive foil;

FIG. 2B is a schematic exploded view of a second embodiment of thedisk-shaped container which incorporates a screen material;

FIG. 2C is a schematic exploded view of a third embodiment of thedisk-shaped container which incorporates another gas permeable materialand an adhesive layer;

FIG. 2D is a cross-sectional view of the disk-shaped container shown inFIG. 2A;

FIG. 2E is a top view of the disk-shaped container shown in FIG. 2A;

FIG. 2F is a top view of an embodiment of the container incorporatedinto a supporting material and provided with holes for passage of gas orvapor;

FIG. 2G is a cross-section view of the disk-shaped container shown inFIG. 2F;

FIG. 3A is a schematic view of a cartridge for holding the disk-shapedcontainers shown in FIGS. 2A-2E;

FIG. 3B is a cross-sectional view of the cartridge shown in FIG. 3Awherein the cartridge includes a plurality of disk-shaped containers;

FIG. 3C is a top view of the cartridge shown in FIG. 3A;

FIG. 4 is a top view of the sterilization delivery system;

FIG. 5 is a bottom view of the sterilization delivery system shown inFIG. 4;

FIG. 6A is a schematic view of the first delivery member;

FIG. 6B is a detailed cross-sectional view of a portion of the firstdelivery member shown in FIG. 6A;

FIG. 6C is a schematic view of the first delivery member shown in FIG.6B wherein an injector lid and cartridges are positioned into thereceiving ports therein;

FIG. 7A is a schematic view of the second delivery member;

FIG. 7B is a top view of the second delivery member;

FIG. 7C is a cross-sectional view of an aperture of the second deliverymember shown in FIG. 7B wherein the cartridge in the upper carouselreceiving port is positioned over the aperture;

FIG. 8 is a cross-sectional view of the injector; and

FIGS. 9A-9E are cross-sectional views schematically depicting theoperation of the injector shown in FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made to the drawings wherein like numerals referto like parts throughout. As an improvement to conventional liquidhydrogen peroxide (H₂ O₂) injection/delivery techniques, the preferredembodiment discloses a unique sterilization system using one or moresolid hydrogen peroxide complex sterilization injectors incorporatedwith a disk delivery system.

FIG. 1A is a schematic illustration of an exemplary sterilization system80 including a sterilization chamber 90 equipped with a solid H₂ O₂complex sterilization injection system 95. As shown in FIG. 1A, theschematic hydrogen peroxide injection system 95 of the present inventioncomprises mainly an injector 500 to create and to inject H₂ O₂ vaporinto a sterilization chamber 90 which contains items to be sterilized,and a delivery system 300 assembled to deliver containers containingsolid H₂ O₂ complex into the injector. As indicated in the block diagramof FIG. 1B, the delivery system 300 and the injector 500 are all underthe control of a controller 50. The controller 50 is a typicalindustrial controller that receives signals from sensors within thedelivery system 300 and the injector 500 and provides control signals tocontrol the operation of these components as will be describedhereinbelow. Further, the controller 50 also receives signals from thesterilization chamber 90 indicative of the status of a sterilizationprocess. As will be appreciated from the following description, thesystem 80 of the preferred embodiment automatically sterilizescomponents within the sterilization chamber 90 in an efficient manner.Further, as will be further explained in detail hereinbelow, containerscontaining solid hydrogen peroxide complex (which will be referred to asperoxide containers) may be loaded onto the sterilization injectionsystem 95 in a cartridge 200 which is configured to hold a number ofperoxide containers. Once a cartridge 200 is loaded, the delivery system300 automatically transfers peroxide containers 100 (FIGS. 2A-2E) intothe injector 500. The injector 500 then injects the gaseous content ofthe container into the sterilization chamber 90 in a manner that will bedescribed hereinbelow. A used peroxide container 100 is, in turn,disposed into a second cartridge (not shown) which holds used peroxidecontainers 100. This above described cycle continues until the lastperoxide container 100 is used and disposed into the used containercartridge. Consequently, the system 80 allows the operator to load aplurality of cartridges 200 into the delivery system wherein eachcartridge 200 has a plurality of peroxide containers 100. Thesecontainers are then delivered to the injector 500 as needed to performsterilization or disinfection of the articles which may be placed intothe sterilization chamber 90. It will be appreciated from the followingdiscussion that the system 80 is efficient to operate due to the abilityto load many peroxide containers 100 at one time and then automaticallyfeed them into the injector 500 as needed as opposed to loading oneperoxide container 100 at a time. The peroxide container 100 to beutilized in the present invention can be manufactured by facilitatingvarious materials and methods. FIG. 2A shows, in exploded view, a diskshaped container 100 for holding the solid peroxide complex that isutilized in the system 80. In the first embodiment, the container 100preferably includes a piece of metallic foil 106, preferably an aluminumfoil, a solid material 108 and a gas permeable material 104. As shown incross-section in FIG. 2D, the metallic foil 106 forms the bottom layerof the disk-shaped container 100, and defines a first surface 105 and asecond surface 107. A presently anticipated preferred solid material isa hydrogen peroxide complex which releases hydrogen peroxide gas uponheating. However, a hydrate complex or an ammonia complex may also beused for the same purposes. In this embodiment, the solid peroxidecomplex 108 is directly placed on the first surface 105 of the aluminumfoil 106. In accordance with the principles of the present invention,the second surface of the aluminum foil 106 preferably comprises areflective surface which is able to reflect the radiation from a heatedobject away. In this respect, this second surface 107 minimizes heatingof the content of the disk shaped container until contact is made with aheated surface and improves thermal conductivity after contact is made.In the present invention, the solid peroxide complex 108 may be in theform of powder, tablets or a dry slurry i.e., a dry paste. The solidperoxide complex 108 is then covered with a gas permeable membrane 104which defines the top layer of the disk shaped container 100. This gaspermeable membrane 104 may be made of medical grade TYVEK™ or SPUNGUARD™materials, or a glass filter so that the hydrogen peroxide gas releasedfrom the complex 108 in response to heating by the injector system 500in the manner described hereinbelow passes through the permeablemembrane 104 before diffusing into the chamber 90.

FIG. 2B shows a second embodiment of the disk-shaped container. In thisembodiment, in order to provide an even distribution and even heating ofall of the solid peroxide complex 108, a screen material 110, such as ametallic or a polymer screen, is pressed over the peroxide complex 108so that the peroxide complex 108 is evenly distributed into the meshedstructure of the screen material 110 in the manner shown in FIG. 2B. Thesolid peroxide complex 108 may be in the form of a slurry (dried slurry)or powder. If the powder form of the solid hydrogen peroxide complex isto be used, the powder could be slightly wetted with hydrogen peroxidesolution (e.g., 30%) and then dried inside the meshed structure to forma dried slurry so that a better adherence to the screen 110 can beprovided. In this respect, both the screen material 110 and the solidperoxide complex 108 are again sandwiched between the aluminum foil 106and the gas permeable membrane 104, as is explained in the firstembodiment. The screen material 110 also provides an advantageousmechanical support for the disk shaped container 100 during variousprocessing and transportation steps. The melting temperature of thescreen material 110 should be higher than the gas release temperature ofthe hydrogen peroxide complex 108. The hydrogen peroxide gas releaseoccurs at a temperature range of 200 to 300° C., more preferably 25° to250° C. In this embodiment, as an alternative to the screen material110, the aluminum foil 106 can be configured to have a plurality ofpockets on the first surface 105 of the aluminum foil 106 to retain thesolid peroxide complex 108 in these pockets. These pockets can be formedon the aluminum foil 106 as an array of square or hexagonal cavitiesusing techniques well-known in the art, such as embossing the aluminumfoil 106.

FIG. 2C also shows a third embodiment for the disk-shaped container 100.In this embodiment, preferably a layer of adhesive 120, preferably ahigh temperature adhesive, may be placed over the first surface 105 ofthe aluminum foil 106. Adhesives 120 on the aluminum foil 106 may, forexample, include, but are not limited to, an acrylic or a silicon basedhigh temperature adhesives. Once the high temperature adhesive (will bereferred to as adhesive) is applied to the first surface 105 of thealuminum foil 106, the solid peroxide complex 108 is disposed over theadhesive layer 120 in the manner shown in FIG. 2C. The solid peroxidecomplex 108 is then covered with the gas permeable membrane 104 as inthe first and second embodiments. The gas permeable membrane 104 canalso be covered with an optional layer of another gas permeablematerial, such as an inflexible material 122, to mechanically reinforcethe underlying flexible membrane 104, or a flexible material to protectthe gas permeable membrane 104. In this respect, the inflexible material122 may be a thin perforated layer of a rigid material such as a layerof aluminum or a rigid polymer. The flexible material could be a thin,perforated metal foil. It is understood that, in this embodiment, theperoxide complex 108 can be held by the adhesive layer 120. The peroxidecomplex is preferably in the form of powder or dried slurry, asdiscussed above in connection with the use of a screen material 110. Asin the case of the screen material 110, the adhesive layer 120 evenlydistributes the solid peroxide complex 108 over the aluminum foil 106and bonds the individual solid particles to the underlying aluminum foil106. The use of adhesive layer 120 provides a significantly uniformlayer of solid hydrogen peroxide complex 108 over the aluminum foil 106which, in turn, provides an even heating of the peroxide complex 108during the process.

Although these three embodiments are the preferred embodiments toconstruct the solid peroxide complex containers 100, it is understood bythose skilled in the art, that the peroxide containers 100 can also bemanufactured in numerous alternative ways. For example, in the firstembodiment, the adhesive layer 120 or the embossment can be applied overthe first surface 105 of the aluminum foil 106. Similarly, in the thirdembodiment the adhesive layer 120 can be replaced by an embossedaluminum layer to evenly distribute and to retain the solid peroxidecomplex 108 over the aluminum foil 106. Further, in the secondembodiment, the adhesive layer 120 and the screen material 110 can beused together to provide a better distribution for the peroxide complex108. In this alternative embodiment, the adhesive layer 120 caninitially be applied over the first surface 105 of the aluminum foil 106so that the peroxide complex 108 and the screen 110 can be placed overthe adhesive layer 120. This embodiment is particularly useful toprepare peroxide containers 100 comprising a significant amount ofperoxide complex 108, if needed. In this case, the combined effect ofthe screen and the adhesive on the metal foil 106 provides an effectivedistribution for the excessive peroxide complex 108.

In accordance with the principles of the present invention the adhesivelayer 120 can be replaced by other alternative adhesives. Examples ofcommon materials to be used as an adhesive include, but are not limitedto, acrylic adhesives such as A10 or A25 (3M brand) or NT100 and NT200AP(Dielectric Polymers brand) and silicon adhesives such as NT1001(Dielectric Polymers brand). These adhesives can also be advantageouslyused to form tapes, double coated tapes and transfer tapes to increasethe uniformity of the adhesive layer.

Additionally, it is also within the scope of the present invention touse alternative materials to replace aluminum foil 106. This can be doneby replacing one side of the gas permeable membrane with an impermeablemembrane, made of material such as MYLAR™, PTFE or a polycarbonate film.Preferably, the impermeable film side forms the bottom surface of thecontainer 100 and the upper surface is gas permeable membrane. The useof an impermeable film eliminates the need to use of reflective metallicfoils. The metallic foil embodiment is particularly useful in conductiveand convective heating, whereas the impermeable film applications aremost useful in connection with irradiative heating such as microwaveheating, RF heating or Infrared (IR) heating. In fact, It will beparticularly advantageous to use disks having permeable layers on boththe top and the bottom of the disks for microwave, RF heating orconvection heating applications.

Alternative heating sources can be used in conjunction with alternativetechniques to prepare hydrogen peroxide complexes. For example, duringthe preparation process, hydrogen peroxide complex can be mixed with asusceptor material, i.e., a material which can easily absorbs heat andtransfers to neighboring material. The susceptor materials absorbs theheat and effectively distributes the heat inside the hydrogen peroxidecomplex body so that hydrogen peroxide can reach the gas releasetemperature. Examples of common materials used as a susceptor include,but are not limited to, carbon black, metallic powders and combinationsthereof.

FIG. 2D shows an exemplary cross-sectional representation of the diskshaped solid peroxide container 100 for the first embodiment. As shownin FIG. 2D, the container 100 can be formed by bonding together theupper gas permeable membrane 104 and the lower aluminum foil 106 alongan edge section 101 surrounding the disk container 100 so that the solidperoxide complex 108 is sandwiched between these two layers.Specifically, in order to seal this edge section 101, a suitableadhesive may be applied into the interface 103 between the edges ofthese layers 104, 106 and the layers are then firmly pressed towardseach other. Additionally, a heat seal can be also applied to seal theedge section 101. Although the construction of the disk shaped container100 is explained for the first embodiment, it is understood by thoseskilled in the art, that the same principles are also applied to theother embodiments.

As illustrated in the plane view of FIG. 2E, once the edge seal iscompleted, the edge section 101 is configured along the sealed section103 to form a plurality of radially distributed tab features 102 alongthe perimeter of the disk container 100. These tab features 102 enablethe disk-shaped container 100 to fit securely into the cartridge 200 andthe apertures of the lower carousel of the delivery system 300 as willbe described hereinbelow.

FIG. 2F and 2G show an alternative embodiment to configure solidhydrogen peroxide containers 100. In this embodiment, after sealing theedge section of the peroxide disk 100, a layer of supporting material130 is attached along the perimeter of the disk container 100 as in themanner shown in FIGS. 2F and 2G. This material layer can, for example,be a layer of durable plastic. Once this layer is attached to theperoxide container 100, a number of holes 132, which are positioned onthe supporting material and around the perimeter of the disk shapedcontainer 100, is configured as in the manner shown in FIG. 2F. Theseholes 132 provide a passage for the gases released from the top gaspermeable layer 104 or 122 during the process. Thus, the gases candiffuse to the opposite side of the container 100. The support 130 cancomprise a sealable surface 135 around the perimeter of the holes 132.

FIG. 3A illustrates a cartridge 200 that receives the disk-shaped solidperoxide containers 100 (or peroxide disks) illustrated in FIGS. 2A-2E.The cartridge 200 has a cylindrical body 203 comprising an openlower-end 206 and a covered upper-end 204 portions. As seen in FIG. 3A,the cartridge 200 further comprises a base section 213 extendingperpendicularly out of the lower-end 206 peripheral of the hollowcylinder 203 that defines a raised surface 212 positioned adjacent thecylindrical body 203 and a recessed surface 210 positioned at the outerextremity of the base section 213. Further, a handle 216 projectsoutward from the outer peripheral of the upper-end 204 of the hollowcylinder 203, which bends down perpendicularly towards the base section213 and into engagement with the correspondingly shaped raised portion212 of the base section 213.

As illustrated in detail in FIG. 3B, the cylindrical body 203 furthercomprises an inner lip section 202 extending inwardly andcircumferentially around the lower-end peripheral of the hollow cylinder203 in the manner shown in FIG. 3B. Referring to FIG. 3B, the bottomsurface 207 of the base section 213 of the cartridge 200 is formed sothat the plane of the bottom surface 207 defines a flat bottom surfacefor the cartridge 200 for creating a seal thereto. FIG. 3C shows that,in plane view, the base section 213 of the cartridge 200 has a hexagonalshape with rounded corners 211. The recessed portion 210 of the basesection surface 213 extends from the side 217a through the opposite side217b in a counter-clockwise manner and is used to rotationally locatethe peroxide container. As shown in FIG. 3C, the walls 214A and 214B ofthe raised section 212 are formed adjacent the outer surface of thecylinder 203. As will be explained further in the application, theentire recessed portion 210 is dimensioned and configured to engage thecartridge 200 with the upper carousel 220 (FIG. 4) of the deliverysystem 300.

As can be seen in cross-section in FIG. 3B, a plurality of peroxidedisks 100 can be stacked into the cartridge 200. In the preferredembodiment, each cartridge 200 contains ten of the peroxide disks 100.Along their vertical axis, peroxide disks 100 are stacked on top of oneanother and parallel to the bottom surface 207 of the cartridge 200 sothat their aluminum foil 106 faces towards the lower end 206 of thehollow cylinder 203. The diameter of the disk 100 is made slightlysmaller than the diameter of the cylinder 203. In this designconfiguration, the flexible tabs 102 help to secure the disks 100 in thecylinder 203 in the manner shown in FIG. 3C. Hence, by means of the tabfeatures 102, the circumferential edge of the peroxide disks 100 clearsthe inner surface of the hollow cylinder 203. The tabs 102 arepreferably flexible so that peroxide disks 100 can be extracted from thecartridge 200, through the inner lip 202, at the lower end 206 of thehollow cylinder 203 in the manner described hereinbelow.

Although, in the preferred embodiment, the peroxide disks 100 arestacked into cartridges 200, it is also within the scope of the presentinvention to use other methods to provide these peroxide disks 100 forthe system 80. For example, a number of peroxide disks 100 can be joinedat their edges in a z-fold fashion and placed into cartridges 200 sothat the peroxide disks 100 can be fed in series into the injector 500.Additionally,. such joined disks can also be rolled onto a core (orrolled without a core) within the cartridge 200 so that the peroxidedisks 100 can be fed in series into the injector 500.

A sterilant delivery assembly 301 of the delivery system 300 is shown intop view in FIG. 4 and in bottom view in FIG. 5. This assembly 301 ispositioned immediately above the injector 500 so as to be able toprovide and remove peroxide disks to and from the injector 500. As shownin FIG. 4, the delivery assembly 301 is designed for handling anddelivering the peroxide disks 100 to the injector 500 via the cartridge200 as well as removing used disks from the injector 500. As explainedin detail hereinbelow, the delivery assembly 301 is rotatable about az-axis that is perpendicular to the plane of the paper in FIGS. 4 and 5and movable along the z-axis to change the relative elevation of thedelivery assembly 301. Further, the delivery assembly 301 includes afirst delivery member 220 and a second delivery member 310 which aremounted on a drive shaft 331, and are movable independently along andabout the z-axis to handle and transport peroxide disks 100 to and fromthe cartridges 200 and the other process stations of the system 80including the injector 500. Since the delivery assembly 301 is rotatableabout the z-axis, as explained more fully below, the first and thesecond delivery members 220, 310 will sweep a generally circular area.In general, all work stations or source and destination cartridges arepositioned within the ambit of the swept area so that the deliverymembers 220, 310 can efficiently handle and deliver the peroxide disks100.

As shown in the top view in FIG. 4, the first and the second deliverymembers 220, 310 are mounted at their mid-point atop a drive shaft 331.Further, the second delivery member 310 is circular in shape andincludes a peripheral guide rail 325 formed on the upper surface 311 ofthe second delivery member 310. The guide rail 325 is configured toreceive a flexible drive belt 312 that is engaged with the guide rail325 so that movement of the belt 312 results in rotation of the seconddelivery member 310 between its initial and extended positions. The belt312 is also engaged with a drive pulley 315 mounted on a pulley supportbrace 316 positioned adjacent the assembly 301.

As shown in the bottom view of FIG. 5, the drive pulley 315 is connectedto a first bi-directional drive motor 404 which is secured by the pulleysupport brace 316 that is mounted over a side wall 407 of the injectorunit 500. Rotation of the drive pulley 315 in one direction or the otherwill cause a corresponding rotational motion of the delivery assembly301 about the drive shaft 331. The delivery members 220, 310 can beselectively raised and lowered from their home positions by a mechanicaldrive train 414, shown in FIG. 5, under the control of the controller 50(FIG. 1B) in the manner described more fully hereinbelow. The driveshaft 331 of the delivery assembly 301 is connected to and controlled bya second bi-directional drive motor 406 through the mechanical drivetrain 414 which extends between and interconnects the drive shaft 331and the drive motor 406. The drive shaft 331 housing 431 is positionedin a secured manner against a side wall 409 of the injector 500 viabolts 433. In the preferred embodiment, the drive motor 406 for thedrive shaft 331 facilitates movement of the drive shaft 331 withoutrequiring the drive trains 414 and the motor 406 to be located on thez-axis. In fact, this off-set or cantilevered configuration of thedriving system leads to a compact arrangement. In particular, the seconddrive motor 406 is mounted on a trapezoid shaped brace 416 which is, inturn, mounted on the same wall 409 of the injector 500 as the driveshaft housing 431.

As shown in FIG. 5, the bottom part of the delivery assembly is providedwith plurality of vacuum means 418A--418B. The vacuum means can be anyof a number of appropriate mechanisms which can pneumatically attach anddetach to a surface. In the preferred embodiment, a suction cup is used.The vacuum means 418A--418B are connected to a selectively operatedvacuum source (not shown) via appropriate hoses or tubing. The vacuumsource can be selectively enabled or inhibited by the controller 50 in amanner well known in the art to pneumatically attach and detach theperoxide disks 100 from their respective positions in the manner thatwill be described hereinbelow.

As illustrated in FIG. 6A, the first delivery member 220 is comprised ofan upper carousel in this embodiment which has a plurality of receivingports 222A-222C that are configured to accommodate various articles suchas cartridges 200 and/or an injector lid 600 as described below. Inparticular, in the preferred embodiment, the upper carousel 220 includesthree "U" shaped receiving ports 222A-222C which are positioned 120degrees apart from each other about the carousel 220 which is attachedto the drive shaft 331 at a center point 234. The upper carousel 220 ispreferably constructed from a metal such as aluminum or durable polymer,or the like.

As shown in FIG. 6B, the U-shaped ports 222A-222C are further configuredto have rectangular "C" shaped tracks 230 which define openings 228 thatface each other. The tracks 230 are dimensioned and positioned so thatthe cartridge 200 and the injector lid 600 (see FIG. 8) can slide in thetracks 225 in FIG. 6C. In particular, the recessed portion 210 fitswithin tracks 230 to retain the cartridge 200 in the carousel 220.

The second delivery member 310 will now be described in reference toFIGS. 7A and 7B wherein the first delivery member 220 has been removedfor clarity. The second delivery member is comprised of a lower carousel310 having a plurality of apertures to accommodate the peroxide disks100. In the preferred embodiment, the lower carousel 310 includes threecircular apertures 350A-350C which are radially distributed about thez-axis and about the drive shaft mounting hole 330 so that the centerpoints of the circular apertures 350A-350C are positioned 120° apartfrom each other. Each circular aperture 350 is configured to have arecessed lip section 322 and a pair of raised surfaces 318, 320. Therecessed lip section 322 extends inwardly and circumferentially aroundthe aperture 350A-350C such that the lip section is able to hold oneperoxide disk 100 by the tab features 102 in the manner shown in FIG.7B.

The first and second raised surfaces 318, 320 surrounding the apertures350 both extend outward from the upper surface of the lower carousel310. The second raised surface 318 is positioned concentrically aroundthe first raised surface 320 which is further positioned concentricallyaround the aperture 350A-350C. The second raised surface 318 is spacedapart from the first raised surface 320 to define a circular slot 319between the first and the second raised surfaces 318,320 so that thecircular slot 319 can receive an o-ring 321.

FIG. 7C shows schematically the way that the delivery system 301 worksand delivers the peroxide disks 100 from the upper carousel 220 to thelower carousel 310. As shown in FIG. 7C, during the operation, the uppercarousel 220 is positioned over the lower carousel 310 so that theo-ring 321 between the raised surfaces 318, 320 seals the bottom surfaceof the cartridge 200 against the raised surfaces 318, 320 of the lowercarousel 330. The upper and lower carousels 220, 310 are then moveddownward so that the bottom surface of the lower carousel 310 seals thehousing 460 of the vacuum means 418A as in the manner shown in FIG. 7C.Once the vacuum is applied through vacuum means 418A, the peroxide disk100 located above the vacuum means 418A is pulled towards the vacuummeans 418A by raising the upper carousel 220 and grabbed by the vacuummeans 418A.

One of the vacuum means 418A, described above in reference to FIG. 5, isthen configured to extend through the aperture 350A and extracts oneperoxide disk 100 from the cartridge 200 in the port 222A and places itinto the aperture 350A. In particular, the vacuum means 418A extendsthrough the aperture 350A and induces the peroxide disk 100 to be pulledthrough the opening 206 in the base 207 of the cartridge 200 (See FIG.3B). As the tabs 102 are somewhat flexible, the tabs 102 deform to allowthe disk 100 to be extracted from the cartridge 200 as the upper andlower carousels 220, 310 are raised. The disk 100 is then positioned inthe aperture 350A with the tabs 102 engaged with the lip 322 in themanner shown in FIG. 7C.

The operation of the delivery system is controlled by the controller 50.Various externally mounted linear and vertical position sensors andswitches 422 (one shown in FIG. 5) provide the information regarding theposition of the upper and lower carousels 220 and 310 to the controller50 which activates various operation steps in the manner that will bedescribed below. The vertical positions of the delivery assembly shaftcan also be mechanically read by a cam and cam follower arrangement,through an electrical analog device such as an optical switch ornumerous other means well known in the art.

As shown in FIG. 4, the system 80 is also equipped with a bar codereader 402A and bar code burners 402B to provide effective handling anddelivery of the peroxide disks 100 in the cartridges 200. The bar codereader 402A reads a bar code on the new cartridges and activates theoperation. The bar code burner 402B burns the bar code onto the emptycartridges by means of an Infrared lamp to mark the cartridge with theused disks (destination cartridge) The bar code reader 402A could seeand optical snesor mounted on a metal frame 400 which is attached to thedelivery system 300 shown in FIG. 4. These and the other aspects of theinvention will be more fully explained hereinbelow.

The operation of the delivery system 300 is as follows:

The system 300 is initialized by the controller 50 rotating the uppercarousel 220 60° counterclockwise from the home position shown in FIG.4. As shown above in the FIG. 6C, a source cartridge 200 containingmultiple new peroxide disks 100 are inserted manually into uppercarousel port 222A after removing any used cartridge in the uppercarousel 220. The upper carousel 220 and the lower carousel 310 arerotated by the controller to receive a destination cartridge 200 at theport 222C. As discussed above, each cartridge contains a bar code whichis read by the bar code reader 402A so that the controller 50 is awarethat the delivery system 300 is loaded with a new cartridge. Then, thecontroller 50 induces the optical heat source 402B to burn the bar codeon the empty destination cartridge 200 in the port 250A of the uppercarousel 220.

The controller then induces the upper carousel 220 to rotate 60°clockwise to its home position (FIG. 4) to align the source cartridge200 in the port 222A of the upper carousel 220 with the aperture 350A inthe lower carousel 310. At this point the delivery assembly 301 isengaged and moves downward along the shaft 331 to a position adjacentthe injector 500. This position is verified by a position sensor so thatthe controller 50 preferably receives a signal indicative of theposition of the lower carousel.

Once the lower carousel is in the lowered position, the first peroxidedisk 100 is pulled out of the source cartridge 200 in the port 222A atthe upper carousel 220 by the vacuum means 418A located under theaperture 350A in the manner shown and described in reference to FIG. 7C.

The delivery assembly 301 moves upward while the upper carousel 220 andthe lower carousel 310 are disengaged.

Further, once the peroxide disk 100 is placed into the aperture 350A inthe lower carousel 310, the vacuum is released thereby positioning thedisk 100 in the aperture 350A.

The lower carousel 310 is rotated 120° clockwise over an opening 602 inthe injector 500 (See FIG. 8) so that the peroxide disk is placed overthe injector opening 602. This movement of the lower carousel 310preferably positions the new disk 100 above the injector opening 602 andimmediately underneath a perforated plate 605. The perforated plate ispositioned under an injector lid 600 via bolts 613 in a manner shown inFIG. 8.

The controller 50 then induces the lower carousel 310 and the uppercarousel 220 to move together to engage so that the injector lid 600 ispositioned over the disk 100 captured in the lower carousel 310 andpositioned over the opening 602 in the injector housing 601. Thedelivery assembly 301 is then moved downward so that the disk 100 ispositioned over the opening 602 of the injector 500 with the lid 600positioned thereon creating a seal. The injector 500 then performs theinjection process that will be described in reference to FIGS. 8 and 9hereinbelow wherein the disk content 108 is heated to produce theperoxide gas.

Subsequently, the delivery assembly 301 then moves upward so as toremove the used disk 100 from the injector 500. During the upwardmotion, the upper carousel 220 and the lower carousel 310 aredisengaged. The lower carousel 310 is then rotated 120° and placed underthe destination cartridge. At this point, the used peroxide disk ispushed into the destination cartridge 200 by the vacuum means 418B andby the downward motion of the upper and lower carousels 220, 310.

The process is then repeated but in the opposite rotational direction.When the destination cartridge is filled with used disks, thedestination cartridge is rotated 60°clockwise and replaced with a fullsource cartridge for another cycle.

FIG. 8 illustrates the components of the injector 500 in greater detail.As described above, the injector 500 receives a peroxide disk 100 fromthe delivery system 300 in the manner described above. The injectorhousing 601 defines an aperture 602 of a chamber 604 formed within thehousing 601 that is configured to receive the peroxide disk 100. Amovable hot plate assembly 606 is positioned within the chamber 602. Themovable hot plate assembly 606 includes a hot plate 608 that will heatthe peroxide disk 100 to produce peroxide gas, in a manner that will bedescribed hereinbelow, and a carriage assembly 610 that is movablebetween a sealed position, as shown in FIG. 8, and an open position asshown in FIG. 9C. As shown in FIG. 8, the hot plate 608 is bolted to thecarriage assembly 610 via bolts 609. The carriage assembly 610 includesan annular flange 612 that is in communication with an o-ring 614positioned on a bottom surface 616 of the chamber 604 when the carriageassembly 610 is in the sealed position.

As will be described in greater detail hereinbelow, the carriageassembly 610 is slidably movable towards the peroxide disk 100. Inparticular, a bellows chamber 620 is also formed within the housing 601so as to be positioned underneath a bottom surface 618 of the carriageassembly 610. The bellows chamber 620 can be alternatively placed undervacuum or exposed to the air. When the bellows chamber 620 is placedunder vacuum, the carriage assembly 610 is urged into the sealedposition wherein the flange 612 is in sealed contact with the o-ring614. The chamber 602 can also be placed under vacuum which results inthe carriage 610 being urged towards the peroxide disk 100 when there isa higher pressure in the bellows chamber 620. In a preferred embodimentusing a stainless steel bellows and carriage 610, at least a 500 Torrdifferential is preferred when a spring 638 is provided. This results inthe flange 612 disengaging from the o-ring 614.

A plurality of communication passageways 630 are formed in the housing601 positioned outward of the bellows chamber 620. The communicationpassageways 630 have an opening 632 that is positioned on the bottomsurface 616 of the chamber 604 inward of the o-ring 614. Thecommunication passageways 630 have an opening 634 at the end oppositethe opening 632 that is in communication with an access opening 636 inthe wall of the sterilization chamber 90.

A spring 638 is attached between a bottom plate 640 of the bellowschamber and the carriage 610. The bottom plate 640 is attached to thehousing 601 via bolts 642 in the manner shown in FIG. 8. The spring 638biases the carriage 610 into the sealed position shown in FIG. 8 whereinthe flange 612 is in contact with the o-ring 614.

The operation of the injector 500 will now be described in reference toFIGS. 9A-9E. In particular, a peroxide disk 100 that is captured withinthe aperture 350A of the lower carousel 310 is initially positionedwithin the aperture 602 in the manner that is described above.Simultaneously, the lid 600 that is captured within the upper carousel220 is then positioned over the aperture 602 in the manner describedabove so that the disk 100 is sealed within the chamber 604. At thistime, the chamber 604 is not under vacuum but the bellows chamber 620 isunder vacuum as is shown in FIG. 9A. Consequently, the carriage 610 ispositioned in the sealed position wherein the annular flange 612 is incontact with the o-ring 614.

Subsequently, as is shown in FIG. 9B, the chamber 604 is evacuated, thenair is introduced into the bellows chamber 620. As shown in FIG. 9C,this results in the carriage assembly 610 moving upwards towards theperoxide disk 100 as a result of the chamber 604 being under vacuum andthe bellows chamber 620 now being at atmospheric pressure. This resultsin the hot plate 608 contacting the peroxide disk 100 pressing againstthe perforated plate 605 which results in peroxide gas being produced.In the preferred embodiment, the surface of the disk 100 adjacent thehot plate 608 is the foil 106 (FIG. 2A) which preferably reflects theheat of the hot plate away from the disk 100 until the plate actuallycomes in contact with the disk 100.

Further, as is shown in FIG. 9C, the movement of the carriage 610 hasresulted in the annular flange 612 disengaging from the o-ring 614 onthe bottom surface 618 of the chamber 604. Consequently, the passages630 now provide communication between the chamber 604 and thesterilization chamber 90.

As the sterilization chamber 90 is under vacuum, the peroxide gas thatis produced as a result of hot plate 608 contacting the peroxide disk100 travels through the passageways 630 through a flow path 199 into thechamber 90 that contains the implements to be sterilized. Once theinjection process is complete, the bellows chamber 620 is then placedunder vacuum as is indicated in FIG. 9D. The combination of the vacuumin the bellows chamber 620 and the spring 638 result in the carriage 610moving back into the sealed position wherein the flange 618 is incontact with the o-ring 614. The spring 638 is used to assure a restposition for the carriage 610. The chamber 604 can then be exposed toair which releases the seal between the upper carriage plate 610 and theinjector housing 601 thereby permitting removal of the used peroxidedisk 100 in the manner described hereinabove. The process can then berepeated with an additional peroxide disk in the same manner.

Hence, the system of the preferred embodiment allows for an automatedsterilization of multiple batches of objects. The operator simply has toinsert a disk laden cartridge 200 into the upper carousel 220 and anempty cartridge 200, and then initiate the sequence. The controller 50will then, in response to a command to sterilize a batch of objectspositioned within the sterilization chamber 90, rotate and lower thecarousels 220, 310 and initiate the vacuum means 418A, 418B so that aperoxide disk 100 is positioned within an aperture 350A-350C in thelower carousel 310. The controller then rotates the lower carousel 310such that the aperture 350 is positioned over the aperture 602 in thehousing 601 of the injector 500 and below the lid 600. During this step,the upper carousel 220 is preferably oriented so that the injector lid600 is also positioned over the aperture 602 in the injector housing601. The upper and lower carousels 220, 310 are then moved so that thedisk 100 is positioned within the injector 500 in a sealed relationship.

The controller 50 then induces the injector 500 to heat the disk 100 bysubjecting the chamber 604 to vacuum and releasing the vacuum within thebellows chamber 620. This results in the hot plate moving towards andcontacting the disk 100 which results in the production of peroxide gas.The movement of the carriage 610 also preferably opens passageways tothe chamber 90 so that the peroxide gas can be circulated into thechamber 90 to sterilize the objects.

Once the controller 50 determines that the injection cycle is complete,the hot plate 608 is retracted and the upper carousel 220 is removed toremove the injector lid 600. The lower carousel 310 is also preferablymoved upward to extract the used disk 100 out of the injector 500. Thelower carousel 310 and the upper carousel 220 are then moved relative toeach other so that the destination cartridge 200 is located on the uppercarousel 220 above the used disk 100 on the lower carousel 310. Thecarousels 220, 310 are then lowered by the controller 50 and the vacuumsystem 418 is activated to position the used disk in the destinationcartridge.

It will be appreciated that the system of the preferred embodimentallows for the user to perform multiple sterilization sequences withoutreloading the system. Further, the system is entirely automated and hasthe benefit of using solid containers of hydrogen peroxide complex torelease hydrogen peroxide vapor. Although the system 80 of the presentinvention uses a hot plate to heat the peroxide disk 100, alternativeheating methods may also be used with this system. As discussed above,these alternative heating methods preferably make use of variousalternative embodiments of the peroxide container 100.

Although the preferred embodiment of the present invention has shown,described and pointed out the fundamental novel features of theinvention as applied to these embodiments, it will be understood thatvarious omissions, substitutions and changes in the form of the detailof the device illustrated, may be made by those skilled in the artwithout departing from the spirit of the present invention.Consequently, the scope of the invention should not be limited to theforegoing discussion but is to be defined by the claims which follow.

What is claimed is:
 1. An injection system for conductively heating a package containing a solid hydrogen peroxide complex which releases hydrogen peroxide vapor upon heating, comprising:a housing with a gas permeable plate which is pressing on a first side of the package; an opening in said housing through which the package can be inserted, said opening being reclosable ; and a surface heated to 25° to 250° C. which is pressing on a second side of the package away from the first side thereof, said surface and said plate forming a space within said opening, said space in connection with a vacuum.
 2. The injection system of claim 1, wherein the gas permeable plate is rigid.
 3. The injection system of claim 1, wherein the surface is mounted on a carriage which moves the surface into contact with said second side of said package.
 4. The injection system of claim 3, wherein the vapor released from said solid hydrogen peroxide complex is released into a first chamber, and wherein the carriage comprises a seal adapted to create a passageway through which the vapor released from said solid hydrogen peroxide complex can pass into a second chamber when said surface is in contact with said second side of said package.
 5. The injection system of claim 4, wherein when said surface is not in contact with said second side of said package, the first and second chambers are sealed from each other.
 6. The injection system of claim 5, wherein said carriage moves from a first position wherein the surface is away from said package to a second position wherein the surface is in contact with said package as a result of pressure differences between said first chamber and a bellows chamber.
 7. The injection system of claim 6 additionally comprising a spring to move the carriage from the second position to the first position when the pressure difference between said first chamber and said bellows chamber is approximately zero.
 8. The injection system of claim 1, wherein the opening is sealable.
 9. The injection system of claim 8, wherein the opening seals directly to the package.
 10. The injection system of claim 8, wherein the opening seals to a support upon which the package is mounted.
 11. The injection system of claim 8, wherein the opening seals to a mechanism which carries the package.
 12. A method of releasing vapor from a package containing a solid hydrogen peroxide complex which releases hydrogen peroxide vapor upon heating, comprising:providing a housing with a gas permeable plate therein; inserting the package into an opening in said housing so as to place a first side of said package into an orientation facing said plate, said opening being reclosable; pressing a surface heated to 25° to 250° C. onto a second side of said package away from the first side thereof, thereby pressing said first side against said plate and heating said package so as to release vapor therefrom, said surface and said plate forming a space within said opening, said space being evacuated.
 13. The method of claim 12, wherein said second side of said package comprises a conductive foil, wherein said conductive foil is heated by conductive heating from said surface. 